I think that's great - who cares if you know what buttons to push if you don't understand why it works? What happens when that button doesn't work for some reason?

Kudos to Perderabo for his always-elightening posts!

And to yls177, don't kill -9 logins... In fact, don't kill -9 anything unless you're unable to kill -1, kill -15, kill -2, etc first!

to livinfree, is there any reason as to dont kill -9 with anything..

will it cause the runlevel to set to 1 which is the single user mode? (or is it 0)

kill -9 sends signal 9 (SIGKILL) to the process you're pointing it at. This particular signal is untrappable by the process, and it is forced to terminate instantly.
On the other hand, if you did a kill -1 <pid>, it would think it was that the parent process had hung up or disconnected (going back to dumb terminals and/or dialing lines) - it's a SIGHUP signal.

There are other signals, and all others can be caught (and ignored or something other than a "kill" will happen - inetd, for instance), but most of the time, there's no reason to use kill -9.

For a list of signals, check out "man kill".